1. Field of the Invention
The present invention relates to a mud motor used in oil and gas operations that is pressure balanced.
2. Description of the Related Art
Standard sealed mud motors typically have radial bearings/assemblies that are exposed to well bore fluids. The fluid that operates the sealed mud motor must pass across the bearing assemblies and out of the sealed mud motor. Typically, the bearing assemblies have seals that prevent pumped fluid from contaminating any grease or oil used in the bearing assemblies. As fluid flows through the sealed mud motor and across the seals and bearing assemblies, a pressure drop occurs between upper and lower seals associated with the bearing assemblies due to the friction loss associated with fluid flowing through the sealed mud motor. This pressure drop can cause the seals to leak, allowing drilling fluid to enter the bearing assemblies and cause premature failure of the bearing assemblies.
Accordingly, there is a need for a sealed mud motor that can balance the pressure drop across the seals/bearing assemblies caused by the friction of the fluid flowing through the sealed mud motor.